New recombinases for genome engineering

位点特异性重组酶是一类以特定和可预测的方式将不同DNA序列拼接在一起的蛋白质。它们在生物技术中被广泛用于操纵植物和动物的基因组。这些蛋白质的一个特别有用的应用是在哺乳动物染色体中插入或删除基因或DNA片段，以研究它们的功能。理想情况下，插入的DNA应该被阻止切除（并且切除的DNA必须被阻止重新插入），这可以通过一组称为丝氨酸整合酶的位点特异性重组酶来完成。史密斯教授是我们中的一员，他发现一种细菌病毒的整合酶phiC31可以在没有任何其他蛋白质参与的情况下促进不可逆的插入或删除。因此，这种蛋白质在实验生物学的几乎所有分支中都得到了广泛的应用。然而，phiC31整合酶并不完美，实际上存在一些主要问题。有时由phiC31整合酶促进的反应是不完全的，有时根本不发生。在基因组计划的过程中发现了许多其他丝氨酸重组酶，其中一些可能比最初的phiC31整合酶更好地用于生物技术。令人惊讶的是，这些新蛋白从未被系统地研究过，以确定它们是否真的比phiC31整合酶更好。我们愿意这样做。

Site-specific recombinases are a class of proteins that splice different DNA sequences together in a specific and predictable way. They are widely used in biotechnology to manipulate the genomes of plants and animals. A particularly useful application of these proteins is to insert or delete genes or segments of DNA in mammalian chromosomes to study their function. Ideally inserted DNA should be prevented from excising (and excised DNA must be prevented from re-inserting) and this can be done with one group of site-specific recombinases called the serine integrases. One of us, Prof Smith, discovered that the integrase from a bacterial virus, phiC31 can promote an irreversible insertion or deletion without the participation of any other protein. This protein has, as a consequence, become very widely used in nearly all branches of experimental biology. phiC31 integrase is not perfect however and in fact suffers from major problems. Sometimes the reaction promoted by phiC31 integrase is incomplete and sometimes it does not happen at all. Many other serine recombinases have been discovered in the course of genome projects and some may be much better than the original phiC31 integrase for use in biotechnology. Surprisingly these new proteins have never been studied systematically in order to determine whether any of them are in fact better than phiC31 integrase. We would like to do this.